python3-setuptools-scm: Update to version 6.4.2

python3-setuptools-scm: Update to version 6.4.2

- Update from version 6.3.2 to 6.4.2
- Update rootfile
- Changelog
	v6.4.2
	   * fix #671 : NoReturn is not avaliable in painfully dead python 3.6
	v6.4.1
	   * fix regression #669: restore get_version signature
	   * fix #668: harden the selftest for distribution extras
	v6.4.0
	   * compatibility adjustments for setuptools >58
	   * only put minimal setuptools version into toml extra to warn people with old
             strict pins
	   * coorectly handle hg-git self-use
	   * better mercurial detection
	   * modernize packaging setup
	   * python 3.10 support
	   * better handling of setuptools install command deprecation
	   * consider ``pyproject.tomls`` when running as command
	   * use list in git describe command to avoid shell expansions while supporting
             both windows and posix
	   * add ``--strip-dev`` flag to ``python -m setuptools_scm`` to print the next
             guessed version cleanly
	   * ensure no-guess-dev will fail on bad tags instead of generating invalid
             versions
	   * ensure we use utc everywhere to avoid confusion

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>